| Author |
Message |
Jim Avery (Boxer12)
Junior Member
Username: Boxer12
Post Number: 162
Registered: 6-2003
| | Posted on Thursday, August 28, 2003 - 9:57 pm: | |
Malcolm, that's interesting. Maybe it is the chip, because there is no flat spot in my car's xcel. |
JRV (Jrvall)
Intermediate Member
Username: Jrvall
Post Number: 2309
Registered: 11-2002
| | Posted on Thursday, August 28, 2003 - 7:41 am: | |
Adam,
yes the metering heads are the Fuel Distribs. No they cannot be recalibrated at home in spare time, requires special calibrating testers. Additionaly there is far more going on in the systems than metering fuel that needs to be analyzed before knowing if in fact it's a fuel ditrib problem.
A good place to start is CO/HC readings...which provide enough data to give clues as to what direction to go in next to isolate where & what the problems are. |
Adam Goldman '86 TR (Icnsltmfg)
Member
Username: Icnsltmfg
Post Number: 609
Registered: 8-2001
| | Posted on Thursday, August 28, 2003 - 7:24 am: | |
Thanks guys...I have used the Techtron, but does not help too much. Where is the metering heads...is that the fuel distributors? Is that something that is easy to recalibrate? The problem is exactly what you said...I get between 3000 and 4000 rpm a total drop in power and hesitation. Someone told me to have the fuel distributors rebuilt. |
Malcolm West (Ferrari_uk_tech)
Junior Member
Username: Ferrari_uk_tech
Post Number: 77
Registered: 7-2003
| | Posted on Thursday, August 28, 2003 - 4:19 am: | |
Jim - I don't think it's only associated with the UK, because we overhaul metering heads for our dealers in the middle east, maybe the calibration set-up for US cars is different, or you guys just drive through the "flat-spot" - it's more noticeable when driving in town as lots of UK Ferrari owners tend to do.
MW |
Jim Avery (Boxer12)
Junior Member
Username: Boxer12
Post Number: 155
Registered: 6-2003
| | Posted on Wednesday, August 27, 2003 - 4:23 pm: | |
Malcolm, Just out of curiosity, why is this particularly a UK problem?? |
Malcolm West (Ferrari_uk_tech)
Junior Member
Username: Ferrari_uk_tech
Post Number: 71
Registered: 7-2003
| | Posted on Wednesday, August 27, 2003 - 9:27 am: | |
This is a common problem with T/R's in the UK, it usually causes a flat spot (hesitation) at around 2000-3000 rpm. The fault is in the metering heads which should produce around 200cc of fuel per minute per cylinder. We generally find that the fuel delivery has dropped to around 160cc of fuel per minute per cylinder. Using a test bed we have the calibration spring re-shimmed to produce the correct fuel delivery to the injectors.
Like Phil, I doubt there will be any faults with the injectors and should you have the metering heads re-calibrated you will find that you will have to re-set the C/O levels.
Any Bosch agent should be able to re-calibrate your heads for you.
MW |
Jim Avery (Boxer12)
Junior Member
Username: Boxer12
Post Number: 152
Registered: 6-2003
| | Posted on Tuesday, August 26, 2003 - 5:27 pm: | |
Adam, Have you tried Techron fuel injector cleaner yet? |
Phil Hughes (Ferrarifixer)
Junior Member
Username: Ferrarifixer
Post Number: 110
Registered: 7-2003
| | Posted on Tuesday, August 26, 2003 - 4:27 pm: | |
Adam, STOP
The injectors are very reliable, and even with marginal spray patterns you'll unlikely feel a hesitation.
Get them tested and perhaps a "sonic bath" if you really feel the desire. It's easy and cheap.
I had a TR job once that was just well down on power, it turned out to have had the plastic injector feed lines close up internally, I think it's due to having some trick fuel added, maybe avgas or something? But otherwise, it'll be a tune up symptom you've got.
And yes, you'll most likely need to tune it after a job like that. But be careful, the mixture adjusters are super sensitive. Fractions of a turn can have "disastrous" effects on your emmissions. (There you go Doc, there's a disastrous you can use freely!) |
Adam Goldman '86 TR (Icnsltmfg)
Member
Username: Icnsltmfg
Post Number: 607
Registered: 8-2001
| | Posted on Tuesday, August 26, 2003 - 1:52 pm: | |
How difficult is it to replace the fuel injectors on the TR. Mine are the originals and I think it is time to do it. It could be the cause of my hesitation that will not go away. After the change do I have to adjust the mixture on the distributors? |